Hazardous gases and chemicals may undergo continuous monitoring during storage and operations such as transfer and processing to ensure that flammable or toxic levels of gases and vapors are not allowed to escape into the atmosphere. Traditional fixed gas detection systems are either of the point or open path types. In the former, the gas must come into physical contact with the point detector; the point detector is usually catalytic or optical for combustible gas detection, and either electro-chemical or solid state (metal oxide) for toxic gases such as hydrogen sulfide. With open path systems, a beam of infrared light from a lamp or laser traverses a predetermined path. The gas to be detected must cross this path.